17 doctors weighed in:

What's the best allergy medicine? Allegra, Claritin (loratadine) or Zyrtec?

17 doctors weighed in
Dr. Duane Gels
Internal Medicine - Allergy & Immunology
3 doctors agree

In brief: Depends, somewhat

Pollen chamber study done yrs ago typical: when pollen blown directly into the faces of allergic patients, both measured symptoms and patient complaints show Zyrtec better, faster; Claritin (loratadine) slower, worse.
Allegra, a close 2nd. But: FDA felt only Zyrtec was effective enough to advertise for animal allergies (remember the barking dog in the ad?). Note: I'm not affiliated with any of these products.

In brief: Depends, somewhat

Pollen chamber study done yrs ago typical: when pollen blown directly into the faces of allergic patients, both measured symptoms and patient complaints show Zyrtec better, faster; Claritin (loratadine) slower, worse.
Allegra, a close 2nd. But: FDA felt only Zyrtec was effective enough to advertise for animal allergies (remember the barking dog in the ad?). Note: I'm not affiliated with any of these products.
Dr. Duane Gels
Dr. Duane Gels
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Dr. Kristin Sokol
Internal Medicine - Allergy & Immunology
3 doctors agree

In brief: Same effects

These three medications do the same thing and are not supposed to make you drowsy, however, Zyrtec seems to work somewhat better than Allegra and Claritin.
I would say Claritin is the least effective out of these three medications.

In brief: Same effects

These three medications do the same thing and are not supposed to make you drowsy, however, Zyrtec seems to work somewhat better than Allegra and Claritin.
I would say Claritin is the least effective out of these three medications.
Dr. Kristin Sokol
Dr. Kristin Sokol
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Dr. Julian Raffoul
General Practice
2 doctors agree

In brief: Patient dependent

Allegra (fexofenadine), Claritin (loratadine), and Zyrtec (cetirizine) are all wonderful non-sedating second generation antihistamines that selectively antagonize peripheral histamine H1receptors.
They are good for relieving allergic rhinitis (sneezing, itchy/watery eyes, and itchy nose/throat). I believe patients should choose the best medicine to take by trial-and-error.

In brief: Patient dependent

Allegra (fexofenadine), Claritin (loratadine), and Zyrtec (cetirizine) are all wonderful non-sedating second generation antihistamines that selectively antagonize peripheral histamine H1receptors.
They are good for relieving allergic rhinitis (sneezing, itchy/watery eyes, and itchy nose/throat). I believe patients should choose the best medicine to take by trial-and-error.
Dr. Julian Raffoul
Dr. Julian Raffoul
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Dr. Luis Matos
Pediatrics - Allergy & Asthma
2 doctors agree

In brief: All 3 are good

Claritin 10 mg is only as good as Chlorfeniramine 4 mg the most effective dose is 20 mg for adults but that causes 12-14% of people to become drowsy.
Zyrtec 10mg causes same level of drowsiness but controls skin , eye and nasal itching. Allegra at 180mg does not cause significant drowsiness but is as effective as Zyrtec. Allegra is very safe it has been tested at twice/day for hives.

In brief: All 3 are good

Claritin 10 mg is only as good as Chlorfeniramine 4 mg the most effective dose is 20 mg for adults but that causes 12-14% of people to become drowsy.
Zyrtec 10mg causes same level of drowsiness but controls skin , eye and nasal itching. Allegra at 180mg does not cause significant drowsiness but is as effective as Zyrtec. Allegra is very safe it has been tested at twice/day for hives.
Dr. Luis Matos
Dr. Luis Matos
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Dr. Doanh Nguyen, md, faaaai
Internal Medicine - Allergy & Immunology
2 doctors agree

In brief: Pretty much the same

They are all long acting antihistamine and are pretty much the same.
The onset of acting is a little different with 1-3 hours for Claritin (loratadine) and faster for others. In some individuals, Zyrtec may cause drowsiness while this side effect does not see with the other two.

In brief: Pretty much the same

They are all long acting antihistamine and are pretty much the same.
The onset of acting is a little different with 1-3 hours for Claritin (loratadine) and faster for others. In some individuals, Zyrtec may cause drowsiness while this side effect does not see with the other two.
Dr. Doanh Nguyen, md, faaaai
Dr. Doanh Nguyen, md, faaaai
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Dr. Corey Clay
Internal Medicine - Allergy & Immunology
1 doctor agrees

In brief: All of them

Some patients have a preference related to efficacy, but most patients find they are each helpful and often make decisions based on price.
Zyrtec and Allegra are a bit stronger whereas Claritin (loratadine) seems to be active longer. Zyrtec might be slightly more potent with faster onset of effect and it is usually my first suggestion

In brief: All of them

Some patients have a preference related to efficacy, but most patients find they are each helpful and often make decisions based on price.
Zyrtec and Allegra are a bit stronger whereas Claritin (loratadine) seems to be active longer. Zyrtec might be slightly more potent with faster onset of effect and it is usually my first suggestion
Dr. Corey Clay
Dr. Corey Clay
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Dr. Efren Rael
Internal Medicine - Allergy & Immunology

In brief: Allergy medicines

It is often a personal choice based on risks/benefits and indication.
Allegra and Claritin (loratadine) are marketed as non-sedating. The package label for Zyrtec suggests about 10% of people can have sedation with Zyrtec, but in some settings, Zyrtec may have more effect. Price is also a factor. It is not uncommon for antihistamines to lose benefit with time due to a phenomenon called allergy priming.

In brief: Allergy medicines

It is often a personal choice based on risks/benefits and indication.
Allegra and Claritin (loratadine) are marketed as non-sedating. The package label for Zyrtec suggests about 10% of people can have sedation with Zyrtec, but in some settings, Zyrtec may have more effect. Price is also a factor. It is not uncommon for antihistamines to lose benefit with time due to a phenomenon called allergy priming.
Dr. Efren Rael
Dr. Efren Rael
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Dr. Zachary Veres
Family Medicine
1 doctor agrees

In brief: Allergies

Allegra (fexofenadine) or Zyrtec are best with less side effects

In brief: Allergies

Allegra (fexofenadine) or Zyrtec are best with less side effects
Dr. Zachary Veres
Dr. Zachary Veres
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